EN 1149-5 is a European standard that specifies the performance requirements for protective clothing that dissipates electrostatic charges. Garments certified under EN 1149-5 form part of a completely earthed system, offering the wearer protection in environments where this is a risk of explosion.
The EN 1149-5 standard
EN 1149-5 is the European standard for garments that protect against electrostatic discharge in environments where there is a risk of explosion, known as ATEX environments.
Annex II, article 2.3 of the ATEX directive 99/92/CE outlines the minimum requirements for protecting workers at risk of explosive atmospheres and determining the criteria for selective equipment and protective systems by stating “Workers must be provided with appropriate working clothing consisting of materials which do not give rise to electrical discharges that can ignite explosive atmospheres”. EN 1149-5 was developed in line with this directive to specify the requirements for protective clothing that dissipates electrostatic charges.
Many workplaces contain or require activities that cause an explosive or potentially explosive atmosphere. Some examples of ATEX environments include petrochemical plants, workplaces that handle fine organic dusts, and work activities that release flammable gases or vapours.
Protective clothing made to EN 1149-5 standard is only accepted in combination with the European Standard 531 or 11612 for flame retardant clothing, due to explosive risk environments also being a fire risk.
EN 1149-5:2018 performance requirements
EN 1149 garments protect the wearer against static electricity, which can cause sparks. As well as ensuring the material is anti-static, EN 1149 also contains specific design requirements to minimise risk.
EN 1149-5 was developed under the scope of the PPE Regulation (EU) 2016/425 to set the performance requirements for the materials of antistatic PPE used for potentially explosive atmospheres. This standard was most recently updated in 2018, giving us EN 1149-5:2018.
EN 1149-5 specifies the performance requirements of the material and design of protective clothing that dissipates electrostatic charges, used as part of a total earth system to avoid incendiary discharges where the minimum ignition energy of an explosive atmosphere is not less than 0,0016 mJ.
In the context of this European Standard, a total earthed system is one in which personnel and other conductors are connected to earth via a resistance of less than 108 ohm (Ω).
The EN 1149-5 material and design requirements do not presume adequate earthing of additional equipment worn or carried in contact with protective clothing. Any additional equipment will fall outside of the scope of this standard. This standard also does not include protection against mains voltage.
As per the EN 1149-5 requirements, it is prohibited to open or take off the EN 1149-5 certified antistatic clothing in the vicinity of, or when handling, flammable or explosive substances.
The electric insulation properties of the protective clothing will be reduced in the event of contact with liquids, moisture, or perspiration. Therefore, this clothing must not be worn in oxygen-enriched environments. The effectiveness of the antistatic proactive clothing can be affected by wear, washing cycles, and dirt.
EN 1149-5 test methods
There are four test methods specified by EN 1149:
- EN1149-1: Test methods for the measurement of surface resistance
- EN1149-2: Test methods for the measurement of the electrical resistance through a material (vertical resistance)
- EN1149-3: Test methods for the measurement of charge decay
- EN1149-4: Garment test method (standard currently under development)
The test methods of EN 1149-1 and EN 1149-3 are applicable to the EN-1149-5 performance requirements for the electrostatic properties of protective clothing.
EN 1149-1
EN 1149-1 is the test method that measures the surface resistance of the fabric to see how well the material allows an electrical charge to move across its surface. This is measured by testing the resistance in Ohms (Ω) across the material surface between two electrodes with a potential of 100±5 V. In order for the garment to pass this test, it has to be ≤ 2,5 * 109 Ω.
EN 1149-3
EN 1149-3 is the test method that measures the charge decay of the material to determine the speed at which the material loses the charge it builds up into the air. In order for the garment to pass this test, the material must lose at least 50% of its electrical charge within four seconds over a set distance (t50% < 4 s or S > 0.2).
EN 1149-5 marking
Antistatic protective clothing that has been tested in accordance with EN 1149-5 will feature the EN 1149 marking of a lightning bolt inside a shield. The marking will also feature the name of the standard (EN 1149-5). This marking is used to show that the material passes at least one of the EN 1149-5 test methods (EN 1149-1 and EN 1149-3).
